display stack trace

[Former Member]

Env: NetWeaver 6.40 SP15

We are getting a class not found exception when we access our J2EE application under AIX. The user sees an SAP supplied error 500 page displaying:

Application error occurred during request processing.

Details: java.lang.NoClassDefFoundError: org/apache/commons/configuration/ConfigurationException

Exception id: [8A2810007002003F0000001000059048000409F3BCDA6B09]

There is no stack trace nor can I find one in the trace file via the logviewer. How do I view the stack trace? Why isn't the stack trace in the trace file?

[Former Member]

Hi,

I have already answered the question in the below thread

Regards,

Harish

(Please award points for helpful answers)

[Former Member]

Stack trace can be cound under "/usr/sap/J2E/JC00/j2ee/cluster/server0/log" in a typical unix environment.

If you cant see error, you may need to adjust error level thru visual administrator under 'Server-Services-Log Configurator-Locations' and choose severity level for each 'err' and 'out', then save configuration. You should be able to see the error in defaultTrace.<num>.trc file.

<a href="http://www.mycgiserver.com/~kaundinya/sdn/Log%20Configurator.JPG">Here</a>is a screen capture which shows how to confire Log Levels.

HTH

--

Venkat

[Former Member]

I really don't understand why SAP thinks that NOT showing the stack trace by default is the right way to do it, but I digress. Every other app server I've used shows the stack trace by default. Why does SAP make developers jump through so many hoops?

In any case, we changed the the logging level and now sometimes we get a stack trace but not always.

How can we get the stack trace displayed on the error 500 page kicked out by SAP?

[Former Member]

Hi Craig,

there is a property of the HTTP service in SAP Web AS that controls whether the stack trace is displayed in the prowser or not. That's the DetailedErrorResponse property of the HTTP Provider Service on the server. Use the Visual Administrator to set that property to true. (see <a href="http://help.sap.com/saphelp_nw04/helpdata/en/a1/50b2424997c911e10000000a1550b0/frameset.htm">this</a> page from the docs as a reference.)

About your general question why this is the default - well, SAP systems are not always dev systems. In cases of productive systems, it's not quite secure to get detailed error messages (say, ones that displayed the full path to the JSP that can't be found, or one that displays the classloaders structure and references, etc.) in the browser. That's why SAP has chosen the secure behavior as default, and gives the option to enable detailed errors in the browser for development systems.

Hope that explains things a bit.

[Former Member]

I realize that the app server is deployed in several environments such as dev, uat and prod and that SAP may want to protect prod as much as possible by using certain default values. My problem as a developer is that I then have to go hunting for documentation on how to change these defaults to what is actually useful to a developer (i.e. getting stack traces or logging output). What's worse, this documentation is not supplied with the product installation. Why hasn't SAP released a consolidated document providing a list of configuration settings that a developer would be interested in changing? Which leads me to the question: why doesn't the SAP installer install documentation on the app server instead of me having to go hunt down SAP notes or ask questions on SDN or use help.sap.com? Even then, I typically find documentation in windoze help format which is generally terse. Accessing the SAP website is slow given the network environment I'm currently in.